CVE-2025-9515 is a vulnerability classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) found in the Multi Step Form plugin for WordPress, developed by mondula2016. The flaw exists in the import functionality of the plugin across all versions up to and including 1.7.25, where the plugin fails to properly validate the file types being uploaded. This lack of validation allows an authenticated attacker with Administrator-level privileges to upload arbitrary files to the server hosting the WordPress site. Because the uploaded files can be of any type, including executable scripts, this can lead to remote code execution (RCE), enabling the attacker to execute arbitrary commands on the server. The vulnerability requires the attacker to have high privileges (Administrator or above) and does not require additional user interaction once authenticated. The CVSS v3.1 base score of 7.2 reflects the network attack vector, low attack complexity, high privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. Although no exploits have been reported in the wild yet, the potential for severe damage exists if exploited. The vulnerability is particularly critical for websites relying on this plugin for form management, as it can compromise the entire web server and potentially the underlying infrastructure.

The impact of CVE-2025-9515 is significant for organizations using the Multi Step Form plugin on WordPress sites. Successful exploitation allows attackers to upload malicious files, potentially leading to remote code execution, full server compromise, data theft, defacement, or use of the server as a pivot point for further attacks. This threatens the confidentiality of sensitive data stored or processed by the website, the integrity of website content and backend systems, and the availability of the web service. Given WordPress’s widespread use globally, especially among small to medium enterprises and content-driven websites, the vulnerability could lead to widespread exploitation if weaponized. Organizations with high-value targets or sensitive data hosted on WordPress platforms are at elevated risk. The requirement for administrator privileges limits exploitation to insiders or attackers who have already compromised lower-level accounts, but the ease of escalating damage once access is gained is high. The absence of known exploits in the wild currently provides a window for remediation before active attacks emerge.

To mitigate CVE-2025-9515, organizations should immediately update the Multi Step Form plugin to a patched version once available from the vendor. Until a patch is released, administrators should restrict plugin import functionality to the minimum number of trusted users and monitor upload activities closely. Implementing web application firewall (WAF) rules to detect and block suspicious file uploads targeting the import endpoint can reduce risk. Additionally, hardening the server by disabling execution permissions in upload directories and employing strict file type whitelisting at the server or application level can prevent execution of malicious files. Regularly auditing user privileges to ensure only necessary users have Administrator access reduces the attack surface. Monitoring logs for unusual file upload patterns or unexpected file types can provide early detection. Organizations should also consider isolating WordPress instances in segmented network zones to limit lateral movement in case of compromise.